package practice.hot100;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Solution15 {
    public List<List<Integer>> threeSum(int[] nums) {
        Arrays.sort(nums);
        int left;
        int right;
        List<List<Integer>> res = new ArrayList<>();
        for (int i = 0; i < nums.length; i++) {
            if (i > 0 && nums[i] == nums[i - 1]) continue;
            left = i + 1;
            right = nums.length - 1;
            while (left < right) {
                if (nums[i] + nums[left] + nums[right] == 0) {
                    List<Integer> tmp = new ArrayList<>();
                    tmp.add(nums[i]);
                    tmp.add( nums[left]);
                    tmp.add(nums[right]);
                    res.add(tmp);
                    while (left < right && nums[left] == nums[left + 1]) left++;
                    while (left < right && nums[right] == nums[right - 1]) right--;
                    left++;
                    right--;
                } else if (nums[i] + nums[left] + nums[right] < 0) {
                    left++;
                } else {
                    right--;
                }
            }
        }
        return res;
    }
}
